NICE: GPs should use FeNO and 'twitchiness' tests to confirm asthma diagnosis

GPs will have to carry out a battery of assessments to ensure they have an ‘objective’ diagnosis of asthma – including exhaled FeNO and bronchial challenge tests – under proposed NICE guidance.

The new draft guidelines completely bypass the option to carry out a trial of therapy as means to diagnose asthma – currently advised by the recently updated gold-standard SIGN/BTS guidelines on diagnosis – and will see GPs required to get extra tests to confirm a diagnosis.

These will include in some cases measurement of airways inflammation and hyper-reactivity – or ‘twitchiness’ – for which tests are currently not widely available, even in specialist services.

According to NICE, new guidelines on diagnosis and monitoring of asthma are needed because ‘there is evidence that incorrect diagnosis is a significant problem’.

Studies suggest up to 30% of people do not have clear evidence of asthma and while some may previously have suffered it, many patients will have been wrongly diagnosed as asthmatic, NICE advisers said.

The move was welcomed by GP experts in respiratory medicine although they cautioned that the guidelines would need significant investment to implement – irrespective of whether GPs are expected to perform the tests themselves in primary care, or to refer more patients to secondary care for investigations.

The draft guidelines cover both children and adults, and key recommendations for those aged over five years include the need to carry out ‘objective’ testing to diagnose asthma, including initial spirometry tests, follow-up bronchodilator reversibility (BDR) tests and exhaled FeNO tests.

Bronchial challenge tests are also recommended in some cases where there is still uncertainty over the diagnosis.

Any patients considered likely to have occupational asthma should be referred to a specialist straight away, while for children aged under five, GPs should treat symptoms based on their clinical judgement and only perform further tests once the child is considered old enough to take part – usually at around five years of age.

Dr Kevin Gruffydd-Jones, GPSI in respiratory medicine who practices in Box, near Bath, said that more sophisticated tests would be required in ‘a significant number of cases’.

He continued: ‘Tests for exhaled nitric oxide to measure inflammation, and airways hyper-reactivity tests for “twitchy” airways are not widely used at present. The guidelines don’t specify whether these extra investigations should be done by GPs or specialists – but whoever does it, this has got big implications if we are going to do more objective tests – it’s either going to mean a lot more referrals to specialist providers, or primary care will need investment to provide these tests.’

NICE draft asthma diagnosis guidelines – key recommendations

Diagnosing asthma: objective tests in adults and children over five

Use spirometry as the first-line investigation in adults and children over the age of five

- Improvement in FEV1 of 12% or more plus increase in volume of 200ml or more, in older patients

Offer a FeNO test in adults and young people older than 16 if considering a diagnosis of asthma

- FeNO of 40 ppb or more indicates positive test

Offer a direct bronchial challenge test with histamine or methacholine in adults and young people older than 16 if there is diagnostic uncertainty after a normal spirometry and either:

- FeNO level of 40 ppb or more and no variability in peak flow readings or

- FeNO level of 39 ppb or less with variability in peak flow readings

Diagnosing asthma in under-fives

Treat symptoms based on observation and clinical judgement in children younger than five years. If asthma still suspected, when the child is old enough to take part in objective tests (usually around the age of five), perform these and review the diagnosis

Looks like more advice from single-condition specialists with no connection with the reality of the crumbling underfunded NHS. All good for where there is a doubt between asthma, COPD or other similar Respiratory problem. We see very few of these. Best suited for secondary care - obvious for GPs to see this from the coalface

The 'draft' NICE tends to be prescriptive and heavily inclined to technology . The draft about using eGFR-cystatinC , 12 months ago,to avoid overdiagnosis of CKD stage 3a(eGFR 45) still has not surfaced and put into practice. This is simply a matter of practically and cost. You see similar arguments in here.The referrals to another clinician to diagnose asthma if initial spirometry shows obstructive picture, will become inevitable......

I see loads of patients misdiagnosed with asthma.It appears that anyone with unexplained breathlessness (alot of which is deconditioning and anxiety) is labelled with asthma and condemned to lifelong inhalers.The very act of taking a puff makes them feel better as they become psychologically dependent and the clinician to continue in the mistaken belief that (s)he made the correct diagnosis in the first place.

Most asthmatics will have normal spirometry at the time of testing so doesn't help to rule in the diagnosis just to distinguish it from COPD.FeNO is used as a surrogate marker for eosinophilic inflammation of the airways.It cannot identify neutrophilic inflammation.

Grrr. This is just ridiculous. NZ is rife with asthma and you can see what happens without inhalers = they get bronchiectasis and pneumonia because they cannot clear the secretions. Spirometry in a five year old is a nonsense. They can nearly do a peak flow. Talk about academic claptrap and ivory towers. I have asthmatics collapsed on my doorstep when its cold, when they have run out of preventative, when its flu season. Shall I sent them all to secondary care? Way to confuse the issue even further. Number of misdiagnosed asthmatics I have seen - two. A teen with a tumour and A surfer with bronchiectasis. Number of asthmatics that die because they get conflicting advice from doctors - maybe Nice should apply themselves to that.